Electrically controlled positioning means



July 6, M. BROWN ELECTRICALLY CONTROLLED POSITIONING MEANS Filed 00t- I3, 1959 '3 Sheets-Sheet 1 FIG. I

MAIN 4 INDICATOR 30 j SOLENOID 2 l2 2 I IO v 74 OMNIRANGE I 2| R 2 I 4 H RECEIVER 22. l l 23 I DISTANCE 'v v v COMPUTER 20 9 9 f A 131 72 REMOTE INDICATORlL mN SOLENOID TRANSMITTER 4| SIGNAL e2 -q RECEIVER 55 s a s u SIGNAL TRANSMITTER /E; ./46 43 SIGNAL RECEIVER SIGNAL TRANSMITTER SYNCHRO FIG. 2 FIG. 3

INVENTOR.

BY MILTON BROWN HUNDREDS DRUM Aff'Ok/VEV July 6, 1965 M. BRowN 3, 3,

ELECTRICALLY CONTROLLED POSITIONING MEANS M/ZTON BROWN July 6, 1965 BROWN 3,193,813

ELECTRIOALLY CONTROLLED POSITIONING MEANS Filed Oct. 13. 1959 3 Sheets-Sheet s 9 l l2 I2 :20 a

135 n5 33 ,437 1' I27 '22 H |36/ 30 n9 I29 (D 6) HUNDREDS 4 DRUM r INVENTOR. MILTON BROWN HI'I'Ok/VEY United States Patent F 3,193,813 ELECTRifiALLY CGNTRULLED PUSITHONiNG MEANS Milton Brown, Glen Rock, Nul assignor to e Bendix Corporation, a corporation of Delaware Original application Oct. 3t), 1953, er. No. 389,390. Divided and this application Get. 13, N59, Ser. No. 846,122 r 4 Claims. ((1 B itt-201) The present application is a division of US. application Serial No. 389,390 filed October 30, 1953, by Milton Brown and assigned to Bendix Aviation Corporation, now abandoned from which a continuation U.S. application Serial No. 137,937 by Milton Brown was filed on September 1, 1961 and assigned to The Bendix Corporationnow U.S. Patent No. 3,184,731. The invention relates to electrically operated indicating systems and particularly to systems in which drum counter type indicators are used.

An object of the invention is to provide an improved arrangement for the electrical operation of one or more drum counter indicators located at a distance from a main indicator. One purpose isto provide novel means for the electrical actuation of remote counters and, in particular, an electrical system that will be simpler and less expensive than those now in use.

A further object is to eliminate the necessity for employing amplifiers and servomotors in the actuating circuits, and to employ synchros for the direct operation of remote indicators. This presents a serious problem, since the usual small synchro suitable for this purpose does not develop enough power for satisfactory operation of the usual drum counter mechanism. Another object of the invention is the origination of a counter construction that can be efficiently operated by low pressure synchros. This is accomplished in general by providing a novel drum structure, including a direct synchro mounting; and a specific feature is the mounting of one or more synchros within the drums of a counter so as to produce an eificient and compact arrangement in which the direct drive connection between a synchro and the associated drum makes it possible for the synchro to rotate such drum directly.

A further feature of this construction is the independent operation of each drum.

A related object is the development of a novel drum counter having two independent drums, each directly rotated by a synchro within the drum; and in an improved form, the incorporation of additional drums, adapted for rotation either by a synchro or by other types of electrical actuating devices.

operate up to four hundred miles, the hundreds drum requires only the digits 1, 2, and 3. A purpose of the invention is to provide a remote indicator arrangement suitable for such systems, which includes a simplified and less expensive construction than that which employs synchro drive for each drum, but which will impart to the hundreds .drum of a remote indicator the limited movementswhich satisfy such systems.

When operating a receiver synchro to locate its rotor in various selected angular positions by providing the required voltages to the windings of the synchro stator, the accepted practice is to connect these windings in series 3,193,813 Patented July 6, 1965 with corresponding windings of the stator of a transmitter synchro, an arrangement commonly called back to back, and thus locate the transmitter rotor, energized from the same source as the receiver rotor, in the desired positions. An object of the invention is to provide novel arrangements for applying the correct voltages to the receiver stator windings to locate the rotor in a desired sequence of positions. Related objects are to provide a switching system for this purpose; to accomplish the indicated objects in a simplified manner by grounding one stator winding; and to simplify the system by employing a phase reversing arrangement.

Another object is to provide a novel. warning, signal, operative to indicate failure of power or signals.

The foregoing and other objects and advantages of the invention will appear more fully hereafter from consideration of the detailed description which follows, considered in conjunction with the accompanying drawings, in which one embodiment of the invention and certain modifications thereof are illustrated. It is to be expressly understood, however, that the drawings are for the purposes of illustration and description and are not to be construed as defining the limits of the invention.

Referring now to the drawings for a more detailed showing of a novel distance indicating system embodying the invention:

FIGURE 1 is a schematic diagram of a distance indicating system, including a main drum counter indicator, a similar remote indicator, and an arrangement for actuating the latter indicator;

FIGURE 2 is a diagram of drive arrangements for the hundreds drum of the remote indicator, including certain modifications;

FIGURE 3 is an end view of a switch cam in FIG- URE 2;

FIGURE 4 is a graph of voltages of synchro stator windings for different rotor positions;

FIGURE 5 is a diagrammatic face view of another form of hundreds drum drive; and

FIGURE 6 is a vertical central section through the switch structure shown in FIGURE 11..

Referring first to FIGURE 1, there is illustrated an automatic distance indicating system of established type widely used on aircraft, which receives beacon signals from an omnirange transmitter, automatically computes the distance to the transmitter and operates a drum counter indicator to show at all times the distance in miles between the aircraft and the transmitter. This arrangement includes a receiver and distance computer 10, which operates through shaft 11 a standard type of drum counter 12. The receiver and computer are so well known that they are shown only diagrammatically. The indicator 12 has the usual units drum 13, tens drum 14 and hundreds drum 1%, with interposed Geneva movement drive of standard type, not shown.

A signal is provided on the main indicator 12 for warning the observer when power failure, or the weakness or lack of signals picked up by receiver it), prevents said receiver from operating properly the indicator 12, in which case the mileage shown thereon would be an unreliable indication of the distance to the transmitter. In the form illustrated, this warning signal comprises a metal strip 20 with intumed end portions 21 pivoted on the shaft 22 of the indicator 12. The strip 20 is located just above the drum surface, and may be swung into or out of position in line with the visible numerals on the drums, being advantageously painted a bright color to attract attention. In the form illustrated in FIGURE 1 the signal strip 20 is narrow and permits observation of the numerals at all times. Means actuated by the power in the receiver 10 is provided for swinging signal 29 into and out of operative position. In the form illustrated in the FIGURE 1, a pinion 23 fixed to a signal strip end portion 21 meshes with a gear sector 24 on a lever arm 25 mounted on pivot 26 carried by a mounting plate, arm 25 having an end operatively connected to a plunger 29 of solenoid 39. As shown in the U.S. application Serial No. 389,390, a spring is arranged to swing the lever arm 25 normally into position where the signal strip 20 overlies the visible numerals on the indicator 12.

When solenoid 30 is energized it retracts plunger 29 against the pressure of the spring, swinging the signal strip 20 laterally out of view through a suitable Window. The solenoid energizing circuit 34 (FIGURE 1) extends to the receiver 10, and is connected in series with the signal circuit therein, so that if the signal becomes too weak to operate indicator 12 properly, or is missing, or

if the power should fail and prevent any signal output,

solenoid 30 would be deenergized, permitting the operating spring to shift the signal strip 20 into operative position. Moreover, the signal strip will retain such position after the receiver 10 is initially turned on until the receiver has heated up and is operating with enough power the same reading, a system that is necessary in larger aircraft, for instance. An improved arrangement for operating remote indicators of this type is shown. Referring again to FIGURE 1, a remote drum type indicators 37 is provided with 21 units drum 38, a tens drum 39, and

at hundreds drum 40 corresponding to drums 13, 14 and 15 of the main indicator 12. As a standard type of drum counter is generally used for the indicator 37, a servo having sufficient power to drive the indicator would be required, together with a servo operating circuit which would include an amplifier to furnish the necessary operating energy. This is avoided by providing at the main indicator 12 a remote indicator drive including an electrical actuating element for each of the drums of the remote indicator 37, and at the remote indicator 37 a separate drive for each of said drums operated by one of said elements. The actuating elements 41, 42 and 43 are driven from shaft 11, as by bevel gears 44 and shaft 45. These elements may be synchros connected through step drive gearing 46, which may be of the mutilated gear type rotating in unison with the general drive of the drums of the main indicator 12, so that the rotor of the tens synchro 42 Will shift of a revolution for each revolution of units synchro 41 attached to shaft 45, and the rotor of synchro 43 will move of a revolution for each revolution of the tens synchro 42. Obviously other well known drive arrangements may be employed.

The drums 33, 39 and 40 of remote indicator 37 are independently mounted, and each is connected to and rotated by a drive element electrically actuated by the corresponding synchro 41, 42, or 43.

In this embodiment the units drive synchro 47, actuated by units transmitter synchro 41, will rotate the remote indicator units drum 38 in synchronism with the main indicator units drum 13; the tens drive synchro 51, actuated by tens transmitter synchro 42, will rotate the remote indicator tens drum 39 in synchronism with main indicator tens drum 14; and the hundreds drive synchro 58, actuated by hundreds transmitter synchro 43, Will rotate the remote indicator hundreds drum 49 in synchronism with the main indicator hundreds drum 15. In this manner all movements of the main indicator drive shaft 11 will operate the remote indicator 37 in exactly the same way as the main indicator 12.

A device having the double function of a shield and a warning signal is provided for the remote indicator 37,

vand operates in the same manner as the signal on the main indicator. It comprises a signal and shield structure including a strip 62 with an inturned end on which is mounted ring gear 64. As described in the US. application Serial No. 389,930, a gear sector 67 meshing with ring gear 64 is mounted on lever arm 68 fixed to a pivot block rocking on pivot '70, and fixed at its other end to a rocking arm operatively engaging a plunger 72 of solenoid 73, whose winding is connected in parallel with the winding of the main indicator solenoid 39 through leads 74 and across the energizing circuit 34 (FIGURE 1). A tension spring normally biases the gear sector 67 into position where the signal and shield strip 62 overlies the numerals on the drums of indicator 37, except when solenoid 73 is energized and rocks the gear sector 67 to shift signal and shield member 62 into invisible position. In the form illustrated in FIGURE 1 the strip 62 is wider than the strip 29, so that it constitutes in effect a shutter which completely'hides the numerals on the drums from view through a suitable window, upon deenergization of the solenoid 73.

The structures illustrated in FIGURE 1 may include the novel drum assembly and cooperating shield and signal member forming the subject matter of the aforenoted US. application Serial No. 389,390 while the present application is directed to the novel electrically controlled positioning means structurally disclosed by FIGURES 2, 3, 5 and 6.

Where only a limited number of digits on the hundreds drum will ever be used, as in the instances heretofore indicated, an arrangement is provided to replace synchro 43 for actuating the remote indicator hundreds drum 40 Which is simpler and substantially less complicated and expensive than the synchro arrangement that has been described. One form of this arrangement employs in place of synchro 43 a rotary switch, and in place of the hundreds drive synchro 58 a simpler electrically actuated device for rotating the hundreds drum 40. In one embodiment of this arrangement, shown in FIGURES 2 and 3, the drive synchro 43 is replaced by a similarly mounted rotary switch, which controls a synchro 190 so as to turn the hundreds drum 40 as well as control the energization of a solenoid 84 for positioning a shield and signal member operating in the same general manner as that described in connection with the operation of signals 20 and 62.

A switch suitable for the proper energizing of solenoid 84 is rotatably mounted in place of synchro 43, and is driven by intermittent gearing 46'. The type of switch 87 shown in FIGURE 8 will be described since it has certain advantages that will appear hereafter. In this construction a block 88 is provided on its cylindrical face with two annular metal conducting strips 89, 90 having contact teeth 91 extending alternately in spaced relation into a central contact zone 92. Strips 89 and 90 are insulated, as by forming block 88 of insulating material. Sliding contact connections with strips 89 and 90 are provided. As shown, brush 93 maintains engagement with strip 89, brush 94 With strip 90, and brush 95 is located in the zone 92 in contact with the teeth 91. Brushes 93 and 94 are connected across a suitable source of electrical energy. When switch 87 is used to operate solenoid 84, brushes 93 and 94 are connected across a DC. potential source 96, this arrangement being indicated in dash lines.

Hundreds drum 40 may likewise be rotated through synchro 58 by a simpler circuit arrangement which can be adapted to different requirements as to the numerals which are to be displayed by the drum, and which eliminates the use of synchro 43. An arrangement of this type, suitable for positioning drum 40 to display either the zero space or the numeral 1, is shown in FIGURE 8. In this arrangement the ends of secondary 97 of the transformer 98, energized from A.C. source 99, are connected to brushes 93 and 94, as shown. Stator 100 of syncho 58 has winding 101 grounded, winding 102 connected to an intermediate point 103 of secondary 97, the

center point of which is grounded, and the third winding 104 connected to brush 95. With this arrangement the voltage applied to stator winding 104 will alternate between the voltages at the ends of transformer secondary 97, while the voltage at windings 101 and 102 remain fixed. This will create two separates fields for rotor 105 of synchro 58, connected to source 99 by leads 106 and 107; and the voltages are selected so that these fields will be at right angles, as hereafter explained. Under these conditions rotor 105 and drum 40 will alternate between two positions at right angles to each other; and by locating the zero or blank space and the numeral 1 at appropriate points on drum 40, these points will be properly located in visible position as the switch 87 rotates.

Under certain conditions it is desirable to expose more than two digits on drums 40. In one aerial navigation system in present operation, four positions are required, carrying the digits 0, 1, 2 and 3 respectively. In one arrangement suitable for this type of system, illustrated in FIGURES 2 and 3, the cylindrical block 88 is provided with a cam surface 108 ararnged to engage the plunger 109 of a standard plunger-actuated reversing microswitch 110 inserted in leads 106 and 107 from rotor 105. Cam 108 is located so that it will engage switch plunger 109 and throw switch 110 when block 88 rotates one step after the numeral 1 has been displayed on drum 40. This will reverse the phase of the voltage applied to rotor 105 during the next two steps, when digits 3 and 4 are displayed, so that the positions of rotor 105 will be 180 offsetfrom its positions during the two preceding steps.

The switch 87 is arranged for the described type of operation, having four equal contact teeth 91, the cam 103 being circumferentially aligned with two consecutive teeth which locate rotor 105 and drum 40 in positions for display of the digits 3 and 4. Drive gearing 46' is there fore constructed in known manner to rotate switch 87 through 90 for each revolution of tens drum 39. It will be evident, however, that this switch system is equally adapted to the location of rotor 105 in a greater number of positions by providing additional contacts for the brushes, connected to the proper voltages.

The voltages applied to each of the three windings of stator 100 in order to position rotor 105 and its associated hundreds drum 40 in a sequence of selected positions, such as those that have been described, can be determined by calculating the relative voltages to be applied to windings 102 and 104, when Winding 101 is grounded, to produce resultant fields that will locate rotor 105 in any desired angular position, in accordance with formulas known to those skilled in this art. The voltage relationships of the windings under these conditions throughout a complete revolution of rotor 105 is a sine function, as indicated in FIGURE 10. From this figure it will be evident that in the first arrangement described, two positions of rotor 105, offset by 90, can be obtained by properly locating point 103 on the transformer secondary 9'7, and by designing this secondary to have the proper voltages at its terminals. These two positions are indicated on the FIGURE 4 graph by the letters A, A and B, B respectively. It will also be evident from this figure that by reversing the phase of the voltage applied to rotor 105, its two succeeding positions, indicated by C, C and D, D on FIGURE 4, will be offset 180 from its two initial positions.

Other switching arrangements may be utilized for applying to windings 102 and 104 the proper voltages for locating rotor 105 and drum 40 in any desired sequence of positions, either directly or by using a reversing switch for simplification purposes in the manner already illustrated, taking advantage of the fact that the two halves of the voltage curve for each winding of the stator 100 are identical except for reversal of phase. One generalized arrangement of this type is illustrated in FIGURES 5 and 6, designed to locate drum 40 in ten successive equally spaced positions for the display of the digits zero through nine. In this embodiment stationary switch disk 115 is mounted in place of block 88, with the drive shaft 116 from gearing 16 journaled in disk 115, said gearing 46 being of the standard ten step type. Mounted on the disk face are inner contact ring 117 and outer contact ring 113 concentric with shaft 116. Sectors in an outer series 119, concentric with said shaft, are connected to appropriate points on transformer secondary 97.

Ten equally spaced sector positions are provided in this arrangement; but two opposite pairs of sectors are joined to form longer sectors for reasons hereafter indicated. Long sector 120 is connected to point 121 at one end of secondary 97. Short sectors 122, 123 and 124 are connected respectively to the upper intermediate point 125, center grounded point 126 and lower intermediate point 127 on secondary 97, while the other long sector 120 is connected to the lower secondary terminal 129. The remaining 3 short sectors 130, 131 and 132 are cross-connected respectively to sectors 124, 123, and 122.

Shaft 116 carries contact arm 133, on which is mounted a brush 134 positioned to engage sectors 119, and a brush 135 bearing against inner contact ring 117, the brushes being electrically connected. A second contact arm 136 fixed to shaft 116 carries brush 137 arranged to contact sectors 119, and electrically connected brush 133 bearing against outer contact ring 118. Inner ring 117 is connected to stator winding 102 through lead 139, while outer ring 118 is connected to stator Winding 104 through lead 140.

The arrangement illustrated will locate rotor 105 and the hundreds drum 40 in ten equidistant positions for the display of the ten digits, as already indicated; and the illustrated position of contact arms 133 and 135 is that at which the digit zero will be exposed. The voltages at the points 121, 125, 126, 127 and 129 on secondary 97 i are selected to maintain the proper relationships between the voltages of the three windings of stator in order to locate rotor properly in the indicated locations; and.these positions for the various digits have been indicated on the graph of FIGURE 4, and in FIGURE 5.

It will be noted that the voltages for successive positions at the peaks of the curves will be the same. Consequently the corresponding sectors are combined to form the long sectors and 128; and the voltages at the three points following each peak are reproduced in inverse order following the next peak. This relationship is the basis for the cross-connection of the shorter sectors 119, and for the possible use of a reversing switch in the manner already indicated. Moreover, the two curves for windings 102 and 104 respectively are identical, except for their ofi set positions, and the angle between arms 133 and 136 is selected to correspond to the angular distance by which these curves are electrically offset.

While the embodiment shown in FIGURES 5 and 6 produces ten drum positions, it is evident that it can be utilized to position rotor 105 in any sequence of positions, simply by connecting sectors 119 to points having the proper voltage values on secondary 97 or other source of variable voltage. Moreover, these rotor positions need not be equally spaced, nor need they involve rotation always in the same direction.

. Although two embodiments of the invention have been illustrated and described in detail, together with certain modifications of parts thereof, it is to be expressly understood that the invention is not limited to the specific disclosure. Various additional changes may be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed is:

1. An electrical control system, comprising a rotor including an actuating inductance connected to an alternating current voltage source and responsive to the direc tion of a magnetic field, a stator including a plurality of associated inductances arranged to establish when energized a resultant magnetic field passing through said rotor inductance, the direction of said field depending on the phase of the energizing alternating current and the relative voltages energizing said stator inductances, rotary switch means for applying to at least one of said stator inductances in two successive sequences a series of differ ent voltages derived from said source, thereby changing the direction of the resultant field and the rotor position, cam means operatively connected to said rotary switch means, and other switch means alternately operable by said cam means for reversing the phase of the alternating current energizing the rotor inductance during the application of the second series, thereby reversing the rotor attitude relative to said magnetic field in the positions assumed during the second sequence.

2. An electrical control system, comprising a rotor including an inductance arranged to align the rotor with the direction of a magnetic field, a stator including a plurality of associated inductances arranged to establish when energized a rotor-actuating resultant magnetic field, the direction of said field and the rotor positions rotating through a cycle of 360 as the voltages of said stator inductances are appropriately varied, each angular position of the rotor being produced by a different combination of stator inductance voltages, the voltages of each stator inductance during the second half cycle being the same as the voltages during the first half cycle with phase reversed, and means for locating the rotor in a series of selected positions, comprising a plurality of different fixed voltages corresponding to the stator inductance voltages at said positions during the first half cycle, means for energizing the rotor inductance from said fixed voltages, switch' means for connecting said fixed voltages to said stator and rotor inductors, said switch means selectively applying predetermined ones of said fixed voltages to said stator inductances, said switch means further applying selectively said rotor voltage directly or reversed in phase in a predetermined correlation to said fixed voltages, to said rotor inductance.

3. An electrical indicator control system, comprising an indicator having a succession of indicating positions, a synchro including a stator and a rotor and having a drive connection with said indicator, means providing a rotor voltage source and a plurality of difierent fixed voltages, switch means for selectively applying predetermined ones of said different voltages to the stator in predetermined sequence and said rotor voltage to said rotor, and said means selectively reversing the phase of the rotor voltage for some or" the predetermined sequence.

4. An electrical indicator control system, comprising an indicating device having a plurality of indicating positions, a rotor for actuating said indicating device, said rotor including an actuating inductance connected to an alternating current voltage source and responsive to the direction of a magnetic field, a stator including a plurality of associated inductances arranged to establish when energized a resultant magnetic field passing through said rotor inductance, the direction of said field depending on the phase of the alternating current and the relative voltages energizing said stator inductances, rotary switch means for applying to at least one of said stator inductances in two successive sequences a series of diiterent voltages derived from said source, thereby changing the direction of the resultant field and the rotor position, cam means operatively connected to said rotary switch means, and other switch means alternately operable by said cam means for reversing the phase of the alternating current energizing the rotor inductance during the application of the second series, thereby reversing the rotor attitude relative to said magnetic field in the positions assumed during the second sequence.

References Cited by the Examiner UNITED STATES PATENTS NEIL C. READ, Primary Examiner.

E. JAMES SAX, IRVING L. SRAGOVV, THOMAS B.

HABECKER, Examiners. 

3. AN ELECTRICAL INDICATOR CONTROL SYSTEM, COMPRISING AN INDICATOR HAVING A SUCCESSION OF INDICATING POSITIONS, A SYNCHRO INCLUDING A STATOR AND A ROTOR AND HAVING A DRIVE CONNECTION WITH SAID INDICATOR, MEANS PROVIDING A ROTOR VOLTAGE SOURCE AND A PLURALITY OF DIFFERENT FIXED VOLTAGES, SWITCH MEANS FOR SELECTIVELY APPLYING PREDETERMINED ONES OF SAID DIFFERENT VOLTAGES TO THE STATOR IN PREDETERMINED SEQUENCE AND SAID ROTOR VOLTAGE TO SAID ROTOR, AND SAID MEANS SELECTIVELY REVERSING THE PHASE OF THE ROTOR VOLTAGE FOR SOME OF THE PREDETERMINED SEQUENCE. 